We report the ⁸⁷Sr optical lattice clock at NIM with a clock laser referenced to a 30cm ULE cavity. Several improvements, such as the atomic temperature and density, the lattice laser frequency stabilization, the fiber noise cancellation, etc, have been made since its first evaluation in 2015. Its systematic frequency shifts are carefully evaluated with a total relative uncertainty of 2.9 10⁻¹⁷. The measured absolute frequency is 429 228 004 229 873.07(0.13) Hz with a relative uncertainty of 3.1 10⁻¹⁶, with reference to the ensemble of primary and secondary frequency standards published in the Circular T bulletin by BIPM through a satellite link.

我们报告了NIM的⁸⁷ Sr 光学晶格时钟，时钟激光器参考 30cm ULE 腔。自 2015 年首次评估以来，已经进行了多项改进，例如原子温度和密度、晶格激光器频率稳定性、光纤噪声消除等。其系统频移经过仔细评估，总相对不确定度为 2.9 10 ^{- 17} . 测量的绝对频率为 429 228 004 229 873.07(0.13) Hz，相对不确定度为 3.1 10 ^-16，参考 BIPM 通过卫星链路在 Circular T 公告中发布的主要和次要频率标准的集合。